1) Field of the Invention
The present invention relates to a technology for generating analysis mesh data.
2) Description of the Related Art
There is an increasing demand that the electric products be light and compact. To fulfill this demand, each part in the electric products should be made light and compact, moreover, the integration between the parts should be a increased.
An improvement in the integration causes an increase of calorific density because of generation of heat in the parts of an electric product. Therefore, when designing the electric product, an analysis of the temperature distribution in the electric product is performed assuming that the electric product is actually functioning.
Reliability of the electric product depends on dynamic factors such as vibrations. Therefore, a dynamic analysis including a vibration analysis of the electric product is as important as the analysis of the temperature distribution (heat analysis).
Heat or vibration analysis is generally performed by numerical analysis such as the finite element method. Softwares that simulate the numerical analysis (numerical analysis simulation softwares) are available. Most of these softwares include three programs: a preprocessor, a solver, and a post-processor. The finite element method is generally carried out according to the following procedure:                (1) generation of input data and conditional equation,        (2) execution of analysis program, and        (3) output of calculated result.This procedure will be explained in detail below.        
(1) The preprocessor or a text editor generates an input data such as analysis mesh data, position data and boundary conditions. Here, analysis mesh data are such that a shape of an object to be analyzed is divided into small portions called as elements and the elements are jointed at points of contact and a whole model can be constructed. Moreover, position data are pieces of position information (coordinate values) set by numbering the elements and the points of contact. Furthermore, a known quantity of the elements, the points of contact or element surfaces is set as the boundary condition. Furthermore, a conditional equation representing characteristics in the elements is generated. Finally, a simulation model is generated.
The preprocessor normally inputs CAD (Computer Aided Design) data representing a shape of an object to be analyzed. The preprocessor analyzes the CAD data, automatically divides the shape into elements, and extracts the analysis mesh data and position data.
(2) The solver solves the simultaneous equations composed of the conditional equations, which have a quantity of the elements and the points of contact has variables.
(3) The post-processor puts the results, which is, for example, the temperature distribution, into visual form and outputs the results.
However, in the numerical analysis simulation software, when an object to be analyzed has a complicated shape, namely, input data (shape data such as CAD data or position data) are complicated multifariously, it is extremely difficult for the preprocessor to generate analysis mesh data accurately from the input data. At the present, although an object to be measured which is larger than that of the conventional one can be handled due to heightening of a speed and a performance of a computer, there arise problems that it is still complicated to automatically divide a construct having fine gaps, and a lot of time is required for rejig or the like and such a construct is difficultly a suitable model.
Particularly an electric product to be provided to end consumer is in a state that a plurality of parts are integrated highly, and has a lot of fine gaps and scattering in shape and size of the parts. For example, particularly as for a circuit board where a plurality of semiconductor elements and ICs are mounted and a junction block where wire harnesses are connected so that a relay, a fuse or the like is integrated, respective parts generate high heat and the entire product shows complicated temperature distribution. Moreover, there are a lot of cases that breakage occurs due to vibration in an on-vehicle application. Namely, in such a product, a breakage or a failure easily occurs due to heat generation or vibration, and thus heat analysis or vibration analysis become more important.